Page 77 - Pharmaceutical Analytical Chemistry III

COLORIMETRIC METHODS IN WATER ANALYSIS :

 The color is developed for the sample and standard
(containing known quantities of the pure substance)
solutions

 The color is measured using either a photometer or
Nessler's tubes.

❖Photometric measurement technique :
Develop the color for the sample and a series of standard.

Measure the absorbance at max using a
spectrophotometer. Determine the unknown
concentration of sample from the standard calibration
curve.